Electric switch



NOV. 11, 1952 KQENIG 2,617,903

ELECTRIC SWITCH Filed Feb. 12, 1949 4 Sheets-Sheet l M. F. KOENIGELECTRIC SWITCH Nov. 11, 1952 4 Sheets-Sheet 2 Filed Feb. 12, 1949 as a62,6 as

M. F. KOENIG ELECTRIC SWITCH Nov. 11, 1952 4 Sheets-Sheet 3 Filed Feb.12, 1949 NOV. 11, 1952 KAOENIG 4 2,617,903

ELECTRIC S WITCH Filed Feb. 12, 1949 4 Sheets-Sheet 4 Patented Nov. 11,1952- ELECTRIC SWITCH Martin F. Koenig, Milwaukee, Wis., assignor toCutler-Hammer, Inc., Milwaukee, Wis., a corporation of DelawareApplication February 12, 1949, Serial No. 76,150

9 Claims.

This invention relates to improvements in electric switches, and moreparticularly to improvements in enclosed, quick make and break switchesof the front-side operated type.

A primary objective of the invention is to generally improve the detailsof construction and assembly of the parts and the operation of switchesof the aforementioned character.

Another object is to provide a compact switch of the aforementionedcharacter wherein the fuses are mounted over the switch parts thustending to reduce the size of the switch and make it more compact.

Another object is to provide a switch of the front-side operated typewherein a rotary motion of a snap action operating mechanism istranslated through a cam surface to move a contact carrying plunger inreciprocal movement at a right angle to the plane of rotary motion.

Another object is to provide a plunger type switch wherein a pluralityof switch units may be placed in tandem for joint operation throughinterconnection of their respective plungers.

Another object is to provide an improved type of individual switch unitin which arcing of the contacts is confined to a substantially enclosedchamber.

Other objects and advantages of the invention will hereinafter appear. v

The accompanying drawings illustrate a preferred embodiment of theinvention, it being understood that the embodiment illustrated issusceptible of modification in respect of certain structuraldetailsthereof without departing from the spirit'and scope of theinvention as defined by the appended claims.

In the drawings,

Figure 1 is a somewhat reduced top plan View of a three-pole, front-sideoperated switch of the fused type; the switch being shown in the offposition and with a fragment of the open covertwo of the fuses, aninsulating cover of one of the switch units, and a cover of one of thecomplementary fuse clamp assemblies being omitted for clarity ofillustration of the parts of the switch.

Fig. 2 is a sectional view on the broken line 2-2 of Fig. 1, with thecover closed, and fixed stops shown in dotted lines.

Fig. 3 is a somewhat reduced side elevation of the guard for theoperating mechanism with the movable stops shown in dotted lines.

Fig. 4 is a sectional view similar to Fig. 2, but with the switchoperating parts in the on position.

Fig. 5 is a sectional view on the broken line 55 of Fig. 4, the switchoperating parts being shown in the on position.

Fig. 6 is a fragmentary elevation view of the details of the switchoperating mechanism, similar to that shown in Fig. 5, but with the partsshown in the off position.

Fig. '7 is a top plan view of the one of the switch units adjacent theswitch operating mechanism, the cover being omitted but with certain ofthe depending portions of the cover being shown in section, and theswitch parts being shown in the on positiona developed view of the camportion of the switch operating mecha nism also being shown in dottedlines, and a fragment of the next adjacent switch unit being shown toillustrate the interrelation of the switch units.

v Fi 8 is a sectional view on the broken line 8-8 of Fig. '1, but withthe switch unit cover and fuse clamp in place and a portion of themounting plate and back wall of the casing being shown; the cam portionof the switch operating mechanism being shown in dotted lines.

Fig. 9 is a sectional view on the broken line 9-9 of Fig. l, but withthe switch Darts shown in the on position.

Fig. 10 is a sectional view on the broken line |0--Hl of Fig. '7, butwith the cover member in assembled position, the fuse clamp beingomitted.

Referring first to Figs. 1 to 6 inclusive, the numeral I0 designates thebody portion of a sheet metal casing or enclosure of substantially thesame construction as that illustrated in the patent to Millermaster etal. No. 2,325,697 to which reference is made for the details ofconstruction thereof. Casing [0 may be provided with suitable knockoutsas shown for example at H, and mounting holes as shown at l2. A cover I3is removably hinged to casing I0 as for example at M in the mannerdisclosed in the aforementioned patent to Millermaster, the switchpreferably embodying as a whole the ornamental design disclosed andclaimed in Design Patent No. 126,465, granted April 8, 1941, toMillermaster and Stevens. A manually releasable cover latch I5 of thetype disclosed in the aforementioned patent to Millermaster et al. No.2,325,697 and more fully described therein is also provided.

Formed integrally with one side wall of casing I0 and bent inwardly at aright angle thereto is a flange portion 16, having an opening I6 Saidopening l6 is of elongated rectangular contour to accommodate and toprovide oscilvabovementioned latory clearance for a flat, substantiallycircular plate-like portion Il (Fig. 2' and Fig. 4) of a die cast metaloperating lever I1, said lever having a handle or hand grip portion 17preferably of the type described in the aforementioned MillermasterPatent No. 2,325,697. As best illustrated in Fig. 1, there is rigidlyattached, as by spot welding, to the one side wall of casing H), a metalmember having a portion l3 and integral portions lB and 18 bent inwardlyat a right angle to portion I8 and an integral intermediate portion [8offset slightly inwardly from and extending upwardly in a plane parallelto said portion I8 Portion lt is provided with two merging circularopenings I 8 (Fig. 2) for cooperation with a peripheral notch l l inplatelike portion I! of operating lever l7 thereby to accommodate thehasps of padlocks for locking the switch in the off position. Portion ltis also provided with a circular opening I 8 (Fig. 5) for registrationwith. circular openings H and H (Figs.v 2 and 4) in plate-like portionllto enable padlocking of the operating lever in the on and offpositions respectively.

Plate-like portion H also has a peripheral, arcuate; ca-m like extensionH (Figs. 2 and. 4) for engagement with a latch member 19 of. the typedisclosed in the aforementionedMillermaster Patent No. 2,325,697 towhich reference is made for the. details of construction andoperationthereof. Latch member I9 is adapted to hook a lug li on cover 13. Thearrangement of portion [1 and latch member. I9 is such. that. the switchoperating lever ll cannot be moved to the on. position when the cover:!3 is open, nor can the cover l3 be opened unless. the operating leverH- is in. the oiT position. However order to provide for manual releaseof the aforedescribed cover interlock afiorded by member. I.9- when theswitch is in the on. position, said member is preferably provided with asubstantially rec.- tangular opening. or slot 19* (adapted to.accommodate the. end. of screw driver or the like), the side wallv ofeasing Hi being provided with a registering opening as shown in dottedlines in Figs. 2. and 4, the operation of saidmanual release being moreparticularly described inthe Millermaster Patent No. 2,325,697.

Lever ll (Fig. 5-) is piv-otally supported upon the inner surfacev ofthe side. wall of casing it as by means of a pin 29,. one end of whichhas. a

flange portion 29 said pin having a relatively ,long intermediate shankportion 23 a reduced intermediate shank portion. 2 9. for insertionthrough a correspondingly shaped opening in lever I7, and a stillfurther reduced portion 29.

for insertion through a correspondingly shaped opening in the side wallof easing E9, pin 28. be.- ing upset over the outer-surface of said sidewall as: at 25 The flange portion 25* abuts the inner surface of a sheetmetal housing member or guard 21 which substantially encloses all of thepin 29. Lever i7 is provided with a. substantially circular portion Hoffset slightly outward for insertion with aclose fit through. a.corresponding opening in spring washer 22 to support the latter when inassembled relation.

The aforementioned guard member 2! (Fig. 3) has flanges 2| and 2| c atopposite ends thereof which are rigidly attached to the side wall ofcasing id, as by means of rivets 23 (Figs. 2 and 3). Guard 2! extendsfrom the bottom wall of easing H] to substantially meet the inner edgeof flange it of casing Ill. Guard 2| is further provided with 2.preferably rectangular opening 2 i and an outwardly extending lug 2 l ethe purposes of which will be. hereinafter described. Guard member 2! isalso provided with two pairs of stops 2i, ZI 2t and 2i the purposes ofwhich will become apparent hereinafter, said stops being formed bypunching and forming inwardly portions of guard 2| to form a cup shapedstructure as shown best in Fig. 3.

Intermediate shank portion 28 of pin 20 is fitted with a sleeve-likebearing 24 (Fig. 5) one end of which is flanged as at 24 said flange.abutting flange portion 25* of pin. 2%). The outer end of bearing 24 isreduced as at 24 for insertion through a corresponding opening in afiat. sheet metal cam operating member 25, and isspun over the outersurface of the latter to rigidly secure the parts together. A shallowannular recess 11* is formed in. plate-like portion I l of. lever. H toprovide clearance for the spunover. end. 24 of bearing 24.

Said cam operating member. 25 is generally of arcuate form and has anarmor extension 25 to which is pivotally connected one end. of a plunger25, as by means of a rivet or pin 27 The other end 26* of plunger 2b isafiorded sliding and. oscillatory clearance. (Figs. 2 and 4). by a slot2 l in guard 2 l. Plunger Z6 is provided with a slot 6. which is adaptedto accommodate the Shani-sofa pin 28 which penetratesalined openings. inthe side wall of casing It and guard. 2t (Fig. 1 and is headed at eachend to'retain the sameirrposition. Pin 28 thus acts to perrnit bothreciprocatory and oscillatory movement of plunger 26. with respect toslot 2H.

Plunger 26 is surrounded by a relatively heavy compression. spring 29,one end of which abuts pin 28 and the other end of which abuts shoulders25 formed on said'plunger 2t; wherefore upon'going over center spring 29acts to efiect snap movement of cam operating member 25 to one or theother of its extreme positions, respectively shown in Figs. 2 and 4.Said member 25 is provided with a pair of angularly spaced integrallugs' 25' and 25, bent inwardly at substantially right angles to theplane of the major portion thereof; the inner edges of which areadaptedfor alternate engage.- ment with the side edges of a cam. member3D to provide a lost motion connection between members 25 and St for apurpose that will hereinafter appear, while the outer edges of said lugsare adapted to alternately engage fixed stops 2 N and Zl of guard 25respectively. (Said fixed stops are shown in dotted lines in Figs. 2 and4- to indicate the aforedescribed relationship of the same with. saidlugs 25 and 25.)

Cam operating member 25 is further provided with. a rigidly attachedoutwardly extending pin 25 which pin extends into an arcuate slot ll inplate-like portion l'i of lever I? to provide a lost motion connectiontherewith. Member 25 is alsoprovided with a pair of arcuate slots25 and25 (Figs. 2 and 4) in each of which is seated a ball bearing, 3 l and 31respectively; said bearings being confined within slots 25 and 25 be ingtrapped between the inner surface of cam member 33 and a bearing plate32 (Fig. 5). Bearing plate '32 is preferably a relatively thin sheetmetal member having an annular portion 32 (shown in doted lines in Figs.2 and 4) and a wing-like arcuate extension 32, the whole of said heatingplate being closely fitted into a shallow recess H of correspondingshape in plate-like portion 11* of lever ll. Said bearing plate 32provides a bearing surface for ball bearings 3| and 3| thus tofacilitate substantially frictionless movement of cam member 30.

Cam member 30 comprises a fiat metal member of the contour bestillustrated in Figs. 2 and 4, having a body portion 30 and an arcuatewinglike" extension 30 the latter providing a cam surface as willhereinafter be described. The body portion 30 has a circular openinghaving annpstanding collar 33 (Fig. 5), pin 20 and sleeve bearing 24being inserted through the aforementioned circular opening to providepivotal support for cam member 30, collar closely fitting bearing 24,the outer edge of collar 30 abutting the inner surface of flange 24 ofbearing24. Body portion 30 is further provided with anintegral arcuatelug 3|! bent outwardly at approximately a right angle to the bodyportion bathe former being in substantially the same I plane as bodyportion 3|] (Fig. 6), while the latter lies in a plane parallel to butoffset inwaiidly from that of body portion 30* (Fig. 5),andan-intermediate sloping portion 30 connectingsurface 30 to surface3|) and extension 30 thdrelationship of the foregoing portions beingsuch as-to present an inclined cam surface to a roller 34 of plunger 33as cam member 30 is moved from one to the other of its extremepositio'ns, this relationship being best illustrated in Figfi'l whereinthe dotted lines represent a developed view of the cam surface of member30. A slight upstanding ridge 30 the purpose of which will hereinafterbe described, is also provided at the'juncture of surfaces 3|! and 30%Contact actuator or plunger 33 is preferably a substantially rectangularbar of insulating material and is notched at one end as at 33- toprovide clearance for a metal roller 34, which is mentioned notch 33 andthrough a centrally located opening in roller 34, said pin being headedon"both ends, thereby to retain the same in assembled relation withplunger 33. Said plunger 33jis biased by means to be hereinafterdescribed to j' extend through a clearance opening 2| in guard member 2|to maintain roller 34 in contact at all times with the cam surface ofcam member 30, lug 2| affording an alinement bearfor plunger 33.

The operation of the aforedescribed snap action switch operatingmechanism is as follows: Assuming the parts to be in the off position asillustrated in Fig. 2, raising of handle of lever |lf results incounter-clockwise rotation of platelike portion l1, it being pivotallysupported on the side wall of casing In by pin 20. A certain amount oflost motion between portions l'!" and cam operating member 25 beingafforded by the interconnection provided by pin 25 and slot camoperating member 25 is not actuated until pin 25 engages the end of slotI! in lever IT. The lost motion having been taken up, further upwardmovement of handle and hence further counter-clockwise movement ofportion IT'- causes cam operating member 25 to similarly move in a.counter-clockwise direction, it also being pivotally supported by pin20. Movement of cam operating member 25 is against the biasing affordedby compression spring 29 and causes an upward and clockwise movement ofplunger 26 relative to its pivotal support, pin 28. A second incrementof lost motion occurs before lug 25 engages notch 33 of cam member 30.This second increment of lost motion having been taken up, furtherupward movement of handle causes further counter-clockwise movement ofportion ll of lever ll, cam operating member 25, and cam member 3|!simultaneously, the last mentioned movement resulting in downwardpassage of surface 30 of cam 30 relative to plunger 33, its roller 34having rolled alon surface 30 Upward movement of handle thus far has notresulted in lateral displacement of contact plunger 33 until roller 34engages ridge 30 on cam member 30, the latter being provided to preventfurther downward movement of cam 30 by virtue of its own weight. At thismoment plunger 26 is carried over center, lever I1 is disengaged fromthe other moving parts by virtue of the aforementioned lost motionconnection, pin 25 and slot H while compression spring 23 propels camoperating member 25, lug 25 of which in turn carries cam member 30, infurther counter-clockwise movement at great speed, cam surfaces 3|] and30 passing rapidly by roller 34, the offset surface 30 permittingplunger 33 and its roller 34 to be laterally displaced outwardly withgreat rapidity. Movement of cam operating member 25 is ultimately haltedby engagement of lug 25 with fixed stop 2| on guard 2|, theaforementioned lost motion connection permitting further movement of cam30, the latter being stopped ultimately by virtue of lug 3|) engagingfixed stop 2| Finally the movement of lever I1 is stopped when handleportion engages member |8 on casing 0.

In moving from the on position as illustrated in Fig. 4 to the offposition illustrated in Fig. 2 the operation is substantially thereverse. Downward movement of handle of lever results in clockwiserotation of plate-like portion H Upon traversing the distance affordedby the lost motion connection, slot I1 and pin 25, cam operating member25 is picked up and likewise rotated in a clockwise direction, lug 25finally engaging notch 3|] of cam member 30 to cause the latter also torotate in a clockwise direction. This latter motion results in passageof surface 30 along roller 34 of plunger 33. Plunger 26 having reachedcenter lever 11 is disengaged from the other moving parts, and spring 29suddenly and with great force propels cam operating member 25, lug 25 inturn carrying cam 30, in further clockwise rotation at great speed. Therapid movement of cam 33 along roller 34 results in a sudden lateraldisplacement of plunger 33 to the left as roller 34 rides up ontosurface 3|) of cam 3|]. Movement of cam 30 is finally halted when lug3|] engages fixed stop 2| on guard 2| while movement of cam operatingmember '25 ceases-when lug 25 strikes fixed stop 2], and lever l? isstopped when its handle li engages member I 8 on casing l0.

It. will be apparent that the operation just described affords a snapaction, quick make and break operation that is substantially immune to"teasing inasmuch as all manual control over the moving parts is lostthe moment plunger 26 and its spring 29 go over center.

Having described the snap action mechanism reference will now be made toFig. 1 wherein is illustrated a switch having three individual switchunits 36, though it is to be understood that any number of said unitsmight be employed. Each of the switch units 36 has a separatecomplementary fuse clamp assembly 31 each of the latter including aninsulating base properly alined with switch units 36 and spacedtherefrom, this arrangement minimizing the cost and weight thereof,though it is to be understood that if desired a single integral base ofproper size might be employed. The fuse clamp assemblies 37 areidentical, as also are the three switch units 35 except as to theircontact carrying plungers as will hereinafter appear. The switch units36 and complementary fuse clamp assemblies 3? are individually removablyattached to a common mounting plate 38 as by screws 39.-

Mounting plate 38 is formed of sheet metal and is provided with flangedportions 35 at opposite side edges thereof, said flanges being adaptedto engage the back wall of easing i5 and provide for removableattachment of mounting plate 3.8 to said back wall of casing It as willhereinafter be described. Flange portions 38 are provided with a pair ofedge notches 33 to accommodate respectively a pair of positioning lugsformed integrally with and extending upwardly from the back wall ofcasing Ill. One of flange portions 38 is further provided with a pair ofedge notches 38 to accommodate a pair of screws 40 for removablyattaching said flange portion to the back wall of casing Hi; while theopposite flange portion 38 is provided with a pair of humps 4| formedintegrally therewith, each of which has an opening to accommodate aselfretaining screw 42 of well known structure for removably attachingsaid flange portion of mounting plate 38 to the back wall of casing it.From the foregoing it will be apparent that the entire switch mechanismmay be readily and easily removed from the casing i by merely looseningscrews 45 and 42 and lifting mounting plate 38 from the casing, all theother switch parts being being attached to mounting plate Baby screws44.

Referring primarly to Figs. '7 to inclusive, the individual switch units86 include a substantially rectangular base 45 molded from insulating,arc resisting material. Insulating base 65 is provided at opposite endsthereof with a pair '1 of integrally formed substantially circularperipheral projections i5 which projections extend upwardly from thebottom plane of said base, said proections 45 being countersunk toaccommodate screws 39 for attachment of the base to mounting plate 38.as hereinbefore described" integrally formed preferably circularpositioning lug (Fig. 8) adapted to cooperate with a core respondingopening in plate 38 is provided on the bottom surface of base 45. Base45 is also pro,- vided at opposite ends thereof witha pair of smaller,semicircular, integrally formed projections 45 which extend downwardly asubstantial distance from the plane of the top surface of theaforementioned base, said last mentioned projections each being providedwith an internally threaded metal insert 45 rigidly attached thereto foraccommodating a cover screw, as will hereinafter be described.

Insulating base 45 is further provided withja pair of recesses 45, 45*,of the contour best 11-; lustrated in Fig. 7, extending downwardly asub-e stantial distance from the top surface thereof, said recesses 4545 serving as contact chambers, as will hereinafter become apparent.Oriel side wall. of each of the recesses 45, 45 has opening into thesame a smaller substantially rectangular recess 45 (Fig. 1 and-Fig. 10)extending downwardly from the top surface of base 45, the rounded bottomwalls of said recesses 45 each serving to support the end of a springas'will hereinafter appear. 2 Within each of the recesses 45, 45and-extending upwardly from the bottom wall and outwardly from theaforementioned side wall thereof is an integrally formed shoulder 41 ofthe contour best illustrated in Figs. 7 and 10; said shoul ders beingformed to cooperate with a depend,- ing portion of a cover member to behereinafter described to afford rather close clearance for a bridgingcontactor 48 as the switch is moved to the "ofi position. Provision ofsaid shoulder 41 and its aforementioned mating member reduces the sizeof the contact chamber and tends to confine any are which may be presenton opening or closure of the contacts as will hereinafter be described.

The, upper surface of base 45 is further provided with a shallow recess45 to accommodate the substantially rectangular flat intermediateportion 49 of a combination stationary contact and terminal lug member49, the terminal lug portion, 49 of said member being supported by asubstantially rectangular integrally formed projection 45 extendingupwardly a substantial distance from the bottom plane of base 45. Theterminal lug illustrated is of the type disclosed in the patent toMillermaster No. 2,193,202" to which reference "is made forthe detailsof construction thereof. Said terminal lug includes a hollow metalmember of substantially rec tangular form in transverse cross section,which member is provided with a relatively large tapped opening toaccommodate the threaded shank of a screw 5|. Intermediate portion 49serving as a strip metal conductor or bus is preferably rigidly attachedto base 45 as by rivets 52. An integral portion 49 of member 49 is bentdownwardly at approximately a right angle to inter-- mediate portion 49to depend into recess 45, the lower end of said portion 49 beingprovided with a suitable contact surface 49 preferably circular, thus toserve as a stationary contact for the switch unit. 7 r

The aforementioned bridging contactor 413 com prises a flat,substantially rectangular metal bar having a pair of preferably circularcontact surfaces 48 projecting forwardly therefrom at each end thereof,said contact surfaces being adapted to engage contact surfaceli) andanother'stawhich it is adapted-to cooperate.

tionary contact to be hereinafter described respectively. The backsurface of contactor 48 is provided near each end thereof with apreferably circular integrally formed lug 48, each for insertion intothe end of a helical compression spring 53 for support thereof, theopposite end of each spring being supported by the bottom walls ofrecesses 45 respectively as hereinbefore described, said springs 53 thusserving to bias bridging contactor 48 to a closed position with respectto its cooperating stationary contacts.

Bridging contactor 48 is supported as a whole by the bottom wall of arectangular notch 33 of plunger 33, said notch extending downwardly fromthe top surface of plunger 33, and being of suincient width to allowcontactor 48 considerable play. The aforementioned bottom wall of notch33 is provided with an integrally formed transverse rib or ridge 33 tointerlock with a corresponding notch 48 formed in the bottom edge ofcontactor 48 as best shown in Figs. 9 and 10, said interlockingpreventing lateral displace- .ment of contactor 48 relative to plunger33.

Plunger 33 is adapted for sliding reciprocal movement in a substantiallyrectangular channel 45 extending through base 45 from side to sidethereof, the bottom wall of said channel being provided with asubstantially rectangular recess 45 (Figs. 8 and 9) for accommodating ahelical compression spring 54. As best shown in Fig. 8, 9

erably of such dimensions as to closely fit within recess 45 forreciprocal movement therein. Spring 54 is positioned so that one endthereof abuts the end wall of recess 45 while the other end of saidspring abuts a side edge of said lug 33 thus tending to bias plunger 33to the closed position of the switch.

Switch unit 36 is also provided with a flat cover member 55 of arcresisting insulating material, said cover member being of substantiallythe same size and peripheral contour as that of base 45 with Extendingoutwardly from each end of cover member 55 are a pair of integrallyformed semi-circular extensions 55* alined with and adapted to cooperatewith the corresponding extensions 45 of base 45, said extensions 55 eachhaving a centrally located, preferably circular opening 55 toaccommodate a screw 56 for insertion therethrough and threading into thealined openings in metal inserts 46 hereinbefore described, thus toprovide for removable attachment of cover member 55 to base 45.

As best shown in Fig. 10, cover member 55 is further provided with apair of integrally formed depending portions 55 so proportioned andalined as to fit downwardly into recesses 45, 45 each to mate withshoulders 41 hereinbefore described and each having an integralextension 55 fitting into recess 45 (Fig. '7) to interlock cover member55 with base 45 and prevent upward displacement of springs 53 withinrecesses 45 (Fig. The bottom surface of cover member 55 is also providedwith an integrally formed substantially rectangular depending portion 55extending the entire width thereof, said portion 55 being soproportioned and alined with respect to base 45 as to extend downwardlyinto channel 45 to form an upper wall thereof and being adapted toclosely fit the upper surface of plunger 33 and prevent upwarddisplacement of the latter. Said portion 55 and cover member 55 arerecessed as at 55 to provide clearance for a pair of rivets 51, theshanks of which are inserted through corresponding and alined openingsin cover member 55 and a bus or conducting member 58, said rivets beingupset over the top surface of bus 58 to rigidly secure the same to thetop surface of cover member 55.

Bus or conducting member 58 is a flat metal plate of the size and shapebest shown in Fig., 1, it being constructed so as to substantially coverthe top surface of cover member 55, the latter being provided with anupstanding integrally formed positioning lug 55 for cooperation with theaforementioned rivets 51 in preventing lateral displacement of bus 58.Formed integrally with bus 58 is a depending portion 58 extendingdownwardly at substantially a right angle thereto through acorresponding opening in cover member 55 and into recess 45 of base 45(Figs. 1 and 9). Said portion 58 is provided at its lower end with apreferably circular contact surface 58 thus forming a stationary contactfor cooperation with one of the contact surfaces 48 on bridgingcontactor 48 as hereinbefore described (Fig, 7).

Rigidly attached to bus 58 as by means of a screw 59 is a fuse clamp 60,cover member 55 being suitably recessed as at 55 to provide clearancefor the head of screw 59 (Fig. 9) Said fuse clamp 60 is illustrated asbeing of the knife blade type disclosed in the patent to MillermasterNo. 2,213,284, though it is to be under stood that any other suitabletype of fuse clamp might be employed.

Each of the ends of bus 58 are upturned throughout the width thereof asat 58 to preventrelative rotary movement of fuse clamp 60 and bus 58,the upturned end 58 being provided to perform that function should it befound desirable to position fuse clamp 60 adjacent there to toaccommodate a different size fuse.

As will be apparent from the foregoing description, the inter-relationof base 45, cover member 55 and plunger 33 provides two substantiallyclosed chambers as indicated by recesses 45 and 45 respectively, eachcontaining a stationary contact 43 and 58 respectively to be bridged bybridging contactor 48 carried by plunger 33 as hereinbefore described.Each of the aforementioned contact chambers is further provided with anL-shaped metal member 6|, Gi respectively (Figs. 7 and 9) to serve as ablowout or means to aid extinguishing of any arc which may be developedon opening or closure of the contacts. Said blowouts are each adapted toabut the respective side walls of recesses 45, 45, respectively, andeach are rigidly attached to the bottom wall of the respective recess asby means of rivets 62, 62, the bottom surface of base 45 being suitablyrecessed as at 63, 63, to provide access to said rivets, said recessesbeing subsequently filled with wax or other suitable insulating materialas shown at 64*, 54 (Fig. 9). Base 45 is also provided with otherirregularly shaped recesses extending upwardly from the bottom surfacethereof, as for example at 45 and 45 (Figs. 9 and 10), the purpose ofwhich is primarily to reduce the weight of base 45.

The operation of the switch units 35 is as follows: Assuming the partsto be in the closed position as shown in Fig. '7, electricalconductivity is afforded from terminal lug 50 and conducting strip 49 tostationary contact portion 49 thence through bridging contactor 48 tostationary contact 58 bus 58 to fuse clampBO. In this osition springs 53hold bridging contactor 48 firmly against its cooperating stationarycontact while spring .54 urges plunger 33 to its extreme right position.As hereinbefore described rotary move.- ment of cam member 30 results in.reciprocal linear movement of plunger 33:; that is, to :the left'fromthe assumed position, against the bias afforded by spring 54. Movementof plunger 33'to the left, after a certain amount of lost motionafforded by the play in the connection between bridging contactor .48and plunger .33 due to :the width of notch 33 ,,results in movement ofbridging :contactor 43 to the left against the bias of springs 53,thusbreaking the circuit at two'points i. e.,'where contact surfaces 28*contact stationary surfaces 49 and 158 respectively. Closure .of :theswitch is accomplished in substantially .the reverse manner, rotarymovement of cam member 30 permitting plunger .33 'to slide ito-therightin response :to the :bias afforded by springs .53 and 54, whilecontactor 48, due to the bias of springs 53, bridges the aforementioned.stationary .contacts, thus completing :the circuit.

As previously mentioned, the construction of each of the switch .units.36 is identical except as to thereciprocating plunger, which in theunit adjacent :to'the snap action mechanism takes the form :of plunger.33 to cooperate with cam :member 30. .In each of the other "Switchunits :the plunger takes-the form best illustrated in Fig. ,1 at I33..Plunger I33 is isimila-rin .construction'to plunger 33 except that oneend thereof instead of being provided with a rolleris::reduced in sizeas at 1.33 to abut thebeveled-end ;of the plunger of the next adjacentswitch'unit, this relationship being best-shown inFig. 7,. Said-reducedportion I33, is provided with a plurality ,of radially extendingrfinsi133", the purpose of whichistoincrease :the over-surface electricalclearance between live partsof adjacent switch units. :It will beapparent from the foregoing that {the operation of :each of the switchunits is similar, and furtherthat the switch :unitsare operatedgjointlyby thesnap action mechanism hereinbefore ;described by virtueof theinterconnection of the individual switch units through the 'alinjed :andsubstantially abutting end to :end relation of their respectiveplungers.It willialso-be'appaa ent that since each of the switchunits isindividually removably attached :to mounting plate '38 and may be addedorremovedwithout disturbance of the other unitsa high'degreeofflexibility in the number of poles provided in the switch is afforded.Moreover, it-wil1be observed from the aforedescribed structurethat thebridging contactors 48 and/or their associated plungers .may, uponremoval of the cover member --55 of the particular switch unit, 'beremoved and/or replaced without disturbing adjacent switchunits, the endto end abutting relationship .of the respective plungers and theaforedescribed removable attachment of such bridging contactor with itsassociated plunger permitting removalof suchcon- .tactors and/or suchplungers while nevertheless rendering the aforedescribed snap actionmechanism .common tolall of .theswitch units utilized.

As hereinbefor'e indicated, each of the switch units 36 has associatedtherewith a complementary fuse clamp assembly-designated generally bythe referenceanumeral 31. Said assembly includes an-open--bottominsulating shell or base '65 .(Fig. .9) of the contour best illustratedin plan viewiin Figrl, Said base 65 .has at opposite ends thereof a pairof integrally formed extensions 112 65 .65 extending upwardly asubstantial dis tance from the bottom planeathereof, said extensionseach having a countersunk opening therein for accommodating screws 39for removable .attachment-of the assembly to mounting plate :33. Adaptedto overlie base 65 and rigidly attached to the upper surface thereof asby means of screws .66, is a bus or conducting member 5] similar toconductingmember 58 on cover member :55 of switch'unit 3,6. Said busmember 761 is :a flat metal member :of substantially rectangular contouras best shown in .Fig. -1. Said bus :member '6'! hasaportion 'iil at oneend thereof servingas the base for a terminal lug 53* which ,iistsimilarto the terminallug shown on'the switch units :36 and islikewise'provided-with ascrew 5|? Said bus member 6! has rigidlyattached thereto as bymeans of a screw 59 a :fuse clamp 1&0 similar to.fuse clamp to attached to bus member 58. .Base fifihas an opening;65:in the upper surface thereof for clearance of said screw 5.9 Busmember 51 is also preferably provided with upturned portion -31 thateach endthereof and extending the width of said member .61. Portion 61incooperation with an :upstanding inte rall formed positioningflug 161is adapted to prevent rotary displacement of fuse clamp 65 when -:inassembled relation as shown :in;Fig. 9. Portion 67 at the opposite -;endof member 161 :is provided in the event that iitli desired toattachxfnse clamp 60*- .at the opposite ends of member :61 toaccommodatea diiferentsizedfuse.

As is apparent from atheioregoing description, fuse clamps 6D and 60 areadapted to accommodate a fuse 63 .(Fig. .1), said fuse rovidingelectrical conductivityfrom fuse clamp 16B .-to;fuse clamp 66*,thencethrough :conductinglmember 16:1 to-terminal lug 50?. As will alsobe apparen in addition to the flexibility of positioning offlthe fuseclamps '63, 163*- on their respective conducting members :to accommodatedifferent sizes of s. a still-greaterflexibility resides the fac thatcasing 10 and mountin pl te :38 mi ht. if desired, ,be elongated topermit further spacing ;of the fuse clam assemblies 13:1 from the switchunits '36 to accommodate still larger g fuses, :the arrangement of thefuse Bil-above the switch .36 nevertheless afiording reater compactness.hencesaving of space.

I claim:

.Acom act switch comp isin combination, t l st one individual switch.unit havin an enclosed arcing chamber and;having a reetilinearlymovable contact actuator, pr sm-ting means for said switch unit separatetherefrom and comprising a cam movable transversely of said contactactuator, .said actuator being biased into cam following engagementawithasaid .carn,

and said switch :operatingrmeans furthencom- :prising .snap acting means"for oscillating said cam -:to impart lateral rectilinear :movements tosaid ,contactactuator against its aforementioned bias.

tact actuator and means for individually biasing said actuators in a.given direction, anoperating mechanism for said switch unitsseparatetherefrom andcomprising a cammovable transversely of the contactactuatorof one ofssaid units, the

.contact actuator of said one unit having-ream following engagement withsaid cam under its aforementioned bias, the other of said individualswitch units being arranged in tandem relation to said one unit withtheir actuators in longitudinal alinement and operatively connected torene der said operating mechanism common to all of said individualswitch units, said operating mechanism further comprising snap actingmeans for oscillating said cam to impart lateral rectilinear movementstosaid contact actuators conjointly against their aforementioned bias.

3. A compact switch affording flexibility in number of poles comprisingin combination, individual switch units in numberdepending upon thenumber of poles desired in the switch, each individual unit having anenclosed arcing chamber and having a rectilinearly movable contactactuator biased in a given direction, an operating mechanism for saidswitch units separate therefrom and comprising a floating cam movabletransversely of the contact actuator of one of said units, the contactactuator of said one'unit having cam followin engagement with said camunder its aforementioned bias, the other of said individual units beingarranged in tandem relation to said one unit with their actuators inlongitudinal alinement in end to end engagement under theiraforementioned bias to render said operating mechanism common to all ofsaid switch units, said operating mechanism further comprising a pivotedhandle and snap lost motion connections between said handle and saidfloating cam for movement of the latter in reverse directionsselectively as a function of reverse movements of said handle to impartlateral rectilinear movements to said contact actuators conjointlyagainst their aforementioned bias.

4, A compact switch Whose size varies directly with the fusing capacityafforded, comprising in combination, at least one individual switch unithaving an enclosed arcing chamber and having a rectilinearly movablecontact actuator biased in a given direction, fuse holding means carriedon the top of said switch unit, a separate complementary fuse holdingassembly in alinement with said switch unit and spaced therefromaccording to the size of fuse utilized, an operating mechanism for saidswitch unit separate therefrom and comprising a cam movable transverselyof said contact actuator, said contact actuator being biased into camfollowing engagement with said cam, and said operating mechanism furthercomprising means for oscillating said cam to impart lateral rectilinearmovements to said contact actuator against its aforementioned bias.

5. A compact switch affording flexibility in number of poles and fusingcapacity, comprising in combination, individual switch units in numberdepending upon the number of poles desired in the switch, eachindividual unit having an enclosed arcing chamber and having arectilinearly movable contact actuator biased in a given direction, fuseholding means carried on the top of each of said switch units,individual complementary fuse holdin assemblies for each of said switchunits and variably spaceable therefrom according to the size of fusesutilized, and an operating mechanism for said switch units separatetherefrom and comprising a cam movable transversely of the contactactuator of one of said units, the contact actuator of said one unithaving a cam following engagement with said cam under its aforementionedbias, the other of said individual switch units being arranged in tandemrelation to said one unit with their actuators in longitudinal alinementin end to end engagement under their aforementioned bias to ren der saidoperating mechanism common to all of said switch units, said operatingmechanism further comprising means for oscillating said cam to impartlateral rectilinear movements to said contact actuators conjointlyagainst their aforementioned bias.

6. A compact switch whose size varies directly with the fusing capacityafforded, comprising in combination, individual switch units in numbercorresponding to the number of switch poles desired and spaced asclosely as their fusing permits, each individual switch unit having anenclosed arcing chamber and having a rectilinearly movable contactactuator biased in a given direction, said actuators being inlongitudinal alinement and in end to end engagement under theiraforementioned bias, an operating mechanism for said switch unitsseparate therefrom but in engagement with the contact actuator of theend one of said switch units to impart to all of said units conjointlylateral rectilinear movements against their aforementioned bias, fuseholding means carried on top of each of said switch units, andindividual complementary fuse holding assemblies for each of said switchunits and variably spaceable therefrom according to the size of fusesutilized, said complementary assemblies being in alinement with theirrespective switch units and spaced from each other as closely as thesize of fuses utilized permits, the space required by said switch unitsand their respective fuse holding assemblies therefore in aggregatecorresponding substantially to the space requirements of the switchfusing.

7. A compact switch having an enclosure, comprising in combination, atleast one individual switch unit having a rectilinearly movable contactactuator biased in a given direction, fuse holding means carried on topof said unit, a complementary fuse holding assembly for said unit, aswitch operating mechanism carried by said enclosure and comprising acam movable transversely of said contact actuator to impart lateralrectilinear movements to said actuator, the latter under itsaforementioned bias having cam following engagement with said cam, and aplate carrying said switch unit and its complementary fuse holdingassembly, the latter being spaced from said switch unit according to thesize of fuse utilized, and said plate therefore be ing of dimensionscorresponding to the fuse size, said plate also having removableconnection with said enclosure to afford joint removal of said switchunit and its complementary fuse holding assembly as a unit leaving saidoperating mechanism undisturbed.

8. A compact switch having an enclosure, comprising in combination,individual switch units in number corresponding to the number of switchpoles desired, each individual switch unit having an enclosed arcingchamber and having a rectilinearly movable contact actuator biased in agiven direction, fuse holding means carried on top of each of saidswitch units, an individual complementary fuse holding assembly for eachof said switch units, a plate upon which said switch units and theirrespective complementary fuse assemblies are carried, said switch unitsbeing spaced on said plate as closely as their fusing permits with theiractuators in longitudinal alinement and in end to end engagement undertheir aforementioned bias, said complementary fuse holding assembliesbeing in alinement with their respective switch units and spacedtherefrom on said plate according to the size of fusin utilized, thedimensions of said plate therefore corresponding to the size of theswitch fusing. and an operating mechanism carried by said .enclosure inengagement with the end one of .said switch units to impart lateralrectilinear movements to all of said units conjointly against theiraforementioned bias, said plate having removable connection with saidenclosure to afiord removal of said switch units and their complementaryfuse assemblies :as a unit leaving said operating mechanism,undisturbed.

9.. A compact switch affording flexibility in number of poles comprisingin combination, individual switch units in number corresponding to thenumber of switch poles desired, each individual switch unit having arectilinearly movable contactactuator biased in a given direction, anoperating mechanism for said switch units separate therefrom comprisinga floating cam movable transversely of the contact actuator of one ofsaid units, the contact actuator of said one unit having cam followingengagement with said cam under its aforementioned bias, theotherREFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS i Number Name Date 1,081,550 Myers Dec. 16, 19131,714,743 Vontobel May '28, 1929 1,863,523 Hammerly June 14, .19321,893,829 Hammerly Jan. 10, 1933 2,221,575 Clark Nov. 12,, 19402,297,090 Weaver Sept. 29,1942 2,325,697 Millermaster et a1. Aug. ,3,1943 2,515,449 Hammerly July 18, 119,50

